JP3930296B2 - Method for manufacturing disc for variator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a variator disk equipped in a toroidal-type continuously variable transmission.
[0002]
[Prior art]
FIG. 3 is a schematic view showing a variator of a toroidal type continuously variable transmission mounted on a vehicle or the like. The variator 10 includes an input shaft 13 that is rotationally driven by a power source 12 of the vehicle, and the input shaft 13 supports input disks 15 in the vicinity of both ends thereof. A spline hole 15a having a plurality of spline grooves is formed at the center of the input disk 15, and the input disk 15 is engaged with the spline shaft 13a of the input shaft 13 by engaging the spline hole 15a. The shaft 13 can rotate integrally with the input shaft 13 in a state where slight movement of the shaft 13 in the axial direction is allowed. The movement of the input disk 15 is permitted in this way because, for example, the right input disk 15 in the figure is biased toward the left input disk 15 side by the hydraulic cylinder 17 connected to the hydraulic power source 16, thereby causing the variator to move. This is because a required terminal load is added to 10. A concave curved track surface 15 b is formed on one side X of the input disk 15.
[0003]
An output portion 18 of the variator 10 is supported at the central portion in the axial direction of the input shaft 13 so as to be relatively rotatable. The output unit 18 includes an output member 19 and a pair of output disks 20 that are supported by the output member 19 so as to rotate together. The output disk 20 faces the track surface 15b of the input disk 15 of the output disk 20. A concave curved raceway surface 20b is formed on one side surface. A sprocket gear 19a that meshes with the power transmission chain 23 is formed on the outer periphery of the output member 19. Further, between the raceway surface 15b of the input disk 15 and the raceway surface 20b of the output disk 20 facing each other, three disc-shaped rollers 21 that are in rolling contact with the raceway surfaces 15b and 20b, respectively, are circumferentially arranged. Is arranged. Each roller 21 is rotatably supported by a carriage 22, and the relative position with respect to each track surface 15 b, 20 b can be adjusted by the carriage 22.
[0004]
Thus, the variator 10 is configured as a so-called double cavity type in which the input disk 15, the output disk 20, and the roller 21 are provided as a pair, and the input disk 15 to the output disk 20. Torque is transmitted through the six rollers 21. Further, by adjusting the positions of the six rollers 21 by the carriage 22 (see the two-dot chain line in FIG. 3), the rotational speed (speed ratio) of the output disk 20 can be increased or decreased.
[0005]
The input disk 15 is made of, for example, bearing steel, and in the manufacture thereof, after the heat treatment and curing of the blank formed by cutting the spline hole 15a and the raceway surface 15b, The raceway surface 15b is finished by cutting or grinding using the inner peripheral surface (minimum inner diameter surface) of the spline hole 15a as a processing reference. Therefore, in order to finish the raceway surface 15b with high accuracy, it is necessary to increase the accuracy of the spline hole 15a. Therefore, after the blank is heat-treated and cured, the spline hole 15a is shaved with a broach to ensure a desired accuracy.
[0006]
When the spline hole 15a is shaved, the other side Y which is the back surface of the raceway surface 15b is used as a processing reference. For this reason, a predetermined accuracy is also required for the other side surface Y. Therefore, as shown in FIG. 4, after the blank 31 is heat-cured, the spline hole 15a is fitted into the small diameter portion 32a of the stepped main shaft 32 of the lathe, and the flat surface 15e near the inner periphery of the one side X is the main shaft. In a state where the flat surface 15e is pressed against the end face of the large-diameter portion 32b of the 32 and the flat surface 15e is used as a processing reference, the edge portion 15d on the outer peripheral side of the one side surface X is flattened by turning, and the edge portion 15d is formed by a surface grinding machine. The accuracy is ensured by grinding the other side Y with the grinding wheel 34 in a state of being placed on the bed 33, that is, in a state where the edge 15d is used as a processing reference (see FIG. 5).
[0007]
[Problems to be solved by the invention]
By the way, when the blank 31 is heat treated, the strain amount of the heat treatment varies depending on the portion. That is, the heat treatment strain on the outer peripheral side of the blank 31 is the largest, then the heat treatment strain inside the raceway surface 15b of the one side X is large, and the heat treatment strain near the inner circumference of the other side Y is the smallest. This is because, as shown by the arrows in FIG. 6, due to the characteristic shape of the variator disk, the outer peripheral side of the blank 31 is deformed so as to fall down toward the right central side in the drawing during heat treatment.
[0008]
Therefore, conventionally, the edge 15d of the input disk 15 is turned with the plane 15e having a relatively large distortion amount and poor accuracy as a machining reference. For this reason, the perpendicularity of the edge portion 15d with respect to the spline hole 15a is deteriorated, and as a result, the perpendicularity between the spline hole 15a before shaving and the other side surface Y which is ground as a processing reference of the shaving is also deteriorated. As a result, when the spline hole 15a is shaved, there is a problem that the broach hits the spline hole 15a and its life is shortened, resulting in high processing cost. Further, there is a problem that the axis of the spline hole 15a after shaving is inclined with respect to the other side surface Y, and the assembly accuracy of the input disk 15 is lowered.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a variator disk capable of satisfactorily ensuring a perpendicularity between a shaving processing reference surface and spline holes before and after shaving. And
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a variator disk manufacturing method of the present invention is used in a variator of a toroidal-type continuously variable transmission, and has a concave curved raceway surface on which a roller rolls on one side surface. A method of manufacturing a variator disk having a spline hole that meshes with an input shaft, wherein an annular protrusion is formed near the inner periphery of the one side surface or the other side surface of the disk blank, and the protrusion is formed. The step of heat-curing the blank, the step of finishing the outer peripheral side edge of the one side of the blank using the end face of the projection as a processing reference, and the other side of the blank using the outer peripheral side edge of the one side as the processing reference The method includes a step and a step of shaving the spline hole in this order using the other side surface as a processing standard (claim 1).
[0010]
According to this variator disk manufacturing method, since the annular projection is formed in the vicinity of the inner periphery of the blank, the heat treatment strain can be reduced. For this reason, when finishing the edge of one side of the blank using the end face of the projection as a processing reference, there is no possibility that the perpendicularity of the edge with respect to the spline hole is greatly collapsed. Therefore, when finishing the other side surface of the blank using the edge as a processing reference, the perpendicularity between the other side surface and the spline hole can be ensured satisfactorily.
[0011]
Preferably, the protrusion is formed on the other side surface (Claim 2). In this case, since the heat treatment strain of the annular protrusion can be further reduced, the perpendicularity between the other side surface and the spline hole is further increased. It can be ensured satisfactorily.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a process diagram showing a method of manufacturing a variator disk to which the present invention is applied. This manufacturing method is applied to the manufacture of the input disk 1 of the variator. First, a blank B is formed by cutting an annular material made of bearing steel or the like obtained by forging or the like.
[0013]
That is, by turning using a cutting tool, as shown in FIG. 1 (a), an annular raceway surface 2 formed of a concave curved surface is formed radially outward of the raceway surface 2 at the radial intermediate portion of one side surface X. And an edge portion 3 formed of a plane substantially perpendicular to the axis, and a first plane 4 formed of a plane perpendicular to the axis in the radial direction of the raceway surface 2, respectively. The protrusions 5 are each formed with a second plane 6 made of a plane perpendicular to the axis on the outer side in the radial direction, and the second plane 6 and the outer peripheral surface 7 are continuous with a tapered surface 8.
[0014]
Further, a spline hole 9 formed of a plurality of spline grooves is formed at the center of the annular material by cutting using the broach C. The processing of the spline hole 9 is performed using the end surface 5a of the protrusion 5 as a processing reference to ensure the perpendicularity of the spline hole 9 with respect to the end surface 5a.
Note that a portion of the blank B excluding the second flat surface 6 and the tapered surface 8 is provided with a predetermined allowance in consideration of heat treatment distortion. The edge 3 protrudes slightly to the right in FIG. 1 from the first plane 4.
[0015]
Next, the blank B obtained by the cutting process is heat-treated and cured to a hardness of, for example, HRC 60 to 64 (see FIG. 1B).
Thereafter, the spline hole 9 of the blank B is fitted into the small diameter portion S1 of the stepped spindle S of the lathe, and the edge portion 3 is turned flat using the cutting tool A. At this time, the end surface 5a of the protrusion 5 of the blank B is pressed against the end surface of the large-diameter portion S2 of the main shaft S, and turning is performed using the end surface 5a as a processing reference (see FIG. 1 (c)). Here, the protrusion 5 is the portion with the least heat treatment distortion, and since there is no possibility that the squareness of the spline hole 9 with respect to the end face 5a is greatly collapsed by the heat treatment, the spline hole 9 and the edge 3 that has been turned are formed. The perpendicularity can be secured satisfactorily.
[0016]
When the turning finish of the edge 3 is completed, the end surface 5a of the protrusion 5 is ground by using a surface grinding machine with the edge 3 as a processing reference (see FIG. 1 (d)). At this time, since the perpendicularity of the edge portion 3 with respect to the spline hole 9 is ensured satisfactorily, the perpendicularity between the ground end face 5a and the spline hole 9 is also ensured favorably.
[0017]
Next, the tooth surface of the spline hole 9 is shaved using the broach C using the end surface 5a as a processing reference (see FIG. 1 (e)). At this time, since the perpendicularity between the end surface 5a and the spline hole 9 before shaving is ensured, it is possible to prevent the broach C from coming into contact with the spline hole 9. For this reason, the life of the broach C can be extended. Further, since the perpendicularity of the spline hole 9 after shaving with respect to the end face 5a can be ensured well, it is possible to prevent the assembly accuracy of the input disk 1 from being lowered.
[0018]
When the shaving of the spline hole 9 is completed, the raceway surface 2 on the one side X side is finished using an NC lathe or a grinding machine with the inner peripheral surface of the tooth surface of the spline hole 4 as a processing reference, and the first plane The required parts such as 4 and the outer peripheral surface 7 are finished by turning or grinding (see FIG. 1 (f)). Thus, the input disk 1 for variator can be obtained.
[0019]
FIG. 2 is a process diagram showing another embodiment. In this embodiment, the protrusion 5 of the blank B is formed in the vicinity of the inner periphery of the one side surface X (see FIG. 2A). Since the heat treatment distortion in the vicinity of the inner periphery of the one side surface X is smaller as it approaches the inner periphery, the outer diameter of the protrusion 5 is set to the minimum necessary.
The blank B is cured by heat treatment (see FIG. 2B), and then the spline hole 9 is fitted into the small diameter portion S1 of the stepped main shaft S of the lathe, and the end surface 5a of the projection 5 is set to the large diameter of the main shaft S. The edge portion 3 is pressed against the end surface of the portion S2 and the edge portion 3 is turned and finished with the end surface 5a as a processing reference (see FIG. 2C). Here, since the protrusion 5 portion has a relatively small heat treatment distortion, the perpendicularity of the spline hole 9 with respect to the end surface 5a can be secured satisfactorily. For this reason, the perpendicularity between the spline hole 9 and the edge portion 3 that has been turned can be ensured satisfactorily.
[0020]
When the turning finish of the edge portion 3 is completed, the second flat surface 6 as the other side surface Y is ground and ground using the edge portion 3 as a processing reference using a surface grinder (see FIG. 2D). At this time, since the perpendicularity of the edge portion 3 with respect to the spline hole 9 is ensured satisfactorily, the perpendicularity between the spline hole 9 and the second flat surface 6 that has been ground can be ensured satisfactorily.
Next, the tooth surface of the spline hole 9 is shaved using the broach C with the second plane 6 as a processing reference (see FIG. 2 (e)). At this time, since the perpendicularity between the spline hole 9 before shaving and the second plane 6 is ensured, it is possible to prevent the broach C from coming into contact with the spline hole 9 and The perpendicularity between the two flat surfaces 6 and the spline holes 9 after shaving can be ensured well.
[0021]
When the shaving of the spline hole 9 is completed, the raceway surface 2 on the one side X side is finished using an NC lathe or a grinding machine with the inner peripheral surface of the tooth surface of the spline hole 4 as a processing reference, and the protrusion 5 The required parts such as the end face 5a and the outer peripheral face 7 are finished by turning or grinding. Thus, the input disk 1 can be obtained (see FIG. 2 (f)).
[0022]
In the case where a spline is adopted as a connection structure between the output disk of the variator and the output member, the above manufacturing method can be applied to this output disk.
[0023]
【The invention's effect】
As described above, according to the variator disk manufacturing method of the first aspect, the edge of one side of the blank is finished with the end face of the protrusion having a small heat treatment strain as the processing reference. There is no possibility that the angle is greatly collapsed, and when the other side surface of the blank is finished using the edge as a processing reference, the perpendicularity between the other side surface and the spline hole before shaving can be secured satisfactorily. For this reason, it is possible to prevent the broach from coming into contact with the spline hole and extend its life, and the manufacturing cost of the disk can be reduced. In addition, since the perpendicularity between the other side surface and the spline hole after shaving can be ensured satisfactorily, it is possible to prevent the assembly accuracy of the disk from being lowered.
[0024]
According to the method for manufacturing a variator disk according to claim 2, since the heat treatment distortion of the annular projection can be further reduced, it is possible to more effectively suppress the broach from hitting the spline hole. At the same time, it is possible to more effectively prevent the disk mounting accuracy from being lowered.
[Brief description of the drawings]
FIG. 1 is a process diagram showing a method of manufacturing a variator disk according to the present invention.
FIG. 2 is a process diagram showing another method of manufacturing a variator disk according to the present invention.
FIG. 3 is a schematic view of a conventional variator.
FIG. 4 is a schematic view showing a conventional edge turning process.
FIG. 5 is a schematic view showing a conventional grinding finishing process of another side surface.
FIG. 6 is an explanatory diagram showing a state of occurrence of heat treatment strain of a disc.
[Explanation of symbols]
1 Input disk 2 Track surface 3 Edge 5 Projection 5a End surface 9 Spline hole B Blank C Broach X One side Y Other side

Claims (2)

This is a method for manufacturing a variator disk that is used in a variator of a toroidal-type continuously variable transmission and has a concave curved raceway surface on which a roller rolls on one side surface and a spline hole that meshes with an input shaft at the center. And
Forming an annular protrusion in the vicinity of the inner periphery of the one side surface or the other side surface of the disc blank;
Heat treating and curing the blank on which the protrusions are formed;
Finishing the outer peripheral side edge of the one side surface of the blank with the end surface of the protrusion as a processing reference;
Finishing the other side of the blank using the outer peripheral edge of the one side as a processing reference;
And a step of shaving the spline hole with the other side as a processing reference in this order. The variator disk manufacturing method according to claim 1, wherein the protrusion is formed on the other side surface.

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